If these lines from Edna St. Vincent Millay don't ring a bell with you, you're not alone. They're from one of her last published collections, Make Bright the Arrows. The mature Millay's work did not go over well with the WWII-era literati and intellectuals. I'll let Answers.com explain:

Carelessly expressed outrage at fascism detracted from Make Bright the Arrows (1940); The Murder of Lidice (1942) was a sincere but somewhat strident response to the Nazis' obliteration of a Czechoslovakian town. She was losing her audience; Collected Sonnets (1941) and Collected Lyrics (1943) did not win it back.

Q: What, if anything, would you doTo keep your country free?... A: LayDown my life! Q: You? You mean you'd die?A: Certainly. (Chorus: That's a lie.)Q: For your country's defense, how much would you give,—If it weren't taxed out of you, I mean. A: All that I have. ...

If, like me, you read and loved "Renascence", you might resonate with the burden of understanding that comes to the "probing sense" of the older poet in these passages.

I'll leave it to you to make your own judgments about Edna St. Vincent Millay's late works. Here's one last selection, a sonnet from Huntsman, What Quarry?